The present invention relates to an imaging device and a manufacturing method thereof, and can be preferably used in an imaging device in which, for example, two photodiodes are formed per pixel.
Imaging devices include one in which two photodiodes are formed per pixel. In such an imaging device, electrons generated in the two photodiodes are used for adjusting a focus (auto focusing) and for still pictures. A focus is adjusted based on the difference between electrons generated, of the two photodiodes, in one photodiode and electrons generated in the other photodiode. Because every pixel can be used for auto focusing in principle, it is said that a focus can be quickly adjusted and in particular a moving picture can be smoothly taken.
On the other hand, a still picture is taken by adding electrons generated in one photodiode to those generated in the other photodiode. That is, a still picture is taken based on the sum of electrons generated in the two photodiodes. As one example of Patent Documents in which such an imaging device is disclosed, Patent Document 1 can be cited.